Art of preparing and making pulp suitable for manufacture into fiberboard and paper



Patented Jan. 26, 1932 UNITED STATES PATENT OFFICE DELL FOREST HARIBAUGH, OF CHICAGO, ILLINOIS, ASSIGNOR T IMPROVED PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS ART OF PREPARING AND MAKING PULP SUITABLE FOR MANUFACTURE INTO FIBER- IBOARD AND PAPER No Drawing. Application filed April 6,

One of the objects of this invention has I been to prepare a chemical combination that manufacture into commercial fiberboard or other fiber products.

Another object has been to develop and reduce to commercial practice a chemical combination suitable for the purpose previously described that would result in a saving under ordinary conditions as regards the cost of pulp preparation from wheat straw or other vegetable fibrous material that lends itself to the commercial practice hereinafter described.

Another object has been the preparation of a fibrous pulp material of Vegetable base that would produce a stronger, flexible pulp than is now ordinarily produced when employing known existing chemical methods.

Another object has been to reduce in vegetable pulp of the character described, the usual excessive hydration that has heretofore prevailed, resulting in an increased yield of fiber of lighter specific gravity which increases the value of reformed products when considered on a commercial tonnage basis.

Another object has been the chemical preparation of a pulp of the character described that would more readily lend itself to amalgamation with ground wood pulp or such chemical pulp as sulphite or sulphate which are prepared underconditions that do not produce excessive hydration in the making of same.

It is well known in the art that making pulp from fibrous material that hydration increases strength at the expense of tare and absorption which in some commercial prodnets of reformed pulp are especially desirable. It has been one of my objects to develop a chemical combination which would produce from straw a pulp that would possess all of these desirable characteristics, namely, strength, tare, and absorption inas closely balanced relationship as practicable in a commercial way. 1v

It is well known to the art that heretofore such chemicals as lime, caustic soda, soda ash, sulphur, copper-as, and soda silicate have 1931. Serial No. 528,242.

been successfully employed either singly or in combination for the purpose of producing pulp from straw, but it is thought that when employed as will hereinafter be described in combination with asuitable gas forming material that their re-employment in this combination will be new, novel, and useful as and for the purposes described.

For the purposes of this invention, I prefer to employ the combination of a suitable quantity of lime in combination with a suitable quantity of caustic soda in combination with a suitable quantity of carbon bi-sulphide, and for most commercial purposes a pulp prepared from the combinations of these reducing agents will be formed preferably when such reducing agents are properly employed.

To illustrate the commercial application of this invention, I prefer when it is desired to produce an especially soft pulp to take 500 pounds of lime, 12 pounds of caustic soda, and combine the same in an aqueous solution using approximately 36 barrels of water. Then discharging this combined chemlcal into a suitableyessel or rotary cooker holding a charge of approximately 150 bales of straw of approximately 60 pounds per bale. This charging requires considerable time to permit this bulk of straw to become thoroughly Wet. When this charging is completed, then 10 pounds of carbon bi-sulphide is added and the rotary sealed. The entire contents are then subjected to continuous steam pressure of from 30 pounds to pounds for approximately three and one-half hours, when the cook will be completed and the pulp Wlll be in proper condition to be reformed into useful products.

When it is desired to produce a coarser,

stiffer, less flexible fiber, I prefer to pursue the method previously described, but employing instead 450 pounds of lime, 12 pounds of caustic soda, 10 pounds of carbon bi-sulphide, and 36 barrels of water, employing steam pressure for from two to two and one-half hours, or such time as would be required to produce the quality desired.

While I have described my preferred chemical combination, as consisting of the chemical combination of lime and caustic soda, in aqueous solution in combination with carbon bi-sulphide and in what I assume as being their correct proportions, I do not wish to be limited either in the precise combination or proportions, but desire to avail myself to the full scope of the appended claims due to the fact that other gaseous material other than carbon bi-sulphide may be used, but it is thought that for the purpose of this invention that carbon bi-sulphide will be found preferable.

Having thus described my invention, what is claimed as new and useful and I desire to protect by Letters Patent is:

1. The proper combination of suitable reducing agents in aqueous solution-with carbon bisulphide as and for the purposes described.

2. The proper combination of lime and caustic soda in aqueous solution with carbon bi-sulphide as and for the purposes described.

3. The combination of suitable reducing agents in aqueous solution together with carbon bi-sulphide operable on the structure of straw or other fibrous material under pressure for a sufficient duration of time to form a commercial pulp from the same.

4. A combination of lime and caustic soda in aqueous solution together with carbon bisulphide operable on the structure of straw or other fibrous material under pressuse for a suflicient duration of time to form commercial pulp.

5. The combination of lime and caustic soda in aqueous solution together with a suitable quantity of mobile liquid gaseous material such as carbon bi-sulphide operable on straw or other fibrous materials under pressure for a sufficient duration of time to form commercial pulp of material value from the same.

6. The combination under pressure of a previously formed chemical substance consisting of an aqueous solution of desirable reducing agents in combination with a suitable quantity of mobile liquid gaseous material such as carbon bi-sulphide capable of forming from straw or other fibrous material a pulp of suitable quality that can be readily formed into manufactured merchandise of conceded commercial value.

7. As an article of manufacture the combination of 500 pounds of lime, 12% pounds of caustic soda in an aqueous solution of 136 barrels of water in combination with 10 pounds of carbon bi-sulphide as and for the purposes described.

S. The process of making fiber pulp comprising treating the fiber with a suitable reducing agent in aqeuous solution with the later addition-of carbon bi-sulphide thereto.

9. The process of making fiber pulp comprising treating 9000 pounds of fibrous material with 500 pounds of lime, 12% pounds caustic soda in an aqueous solution of 36 barrels of water with the later addition of 10 pounds of carbon bi-sulphide thereto.

10. The process of making fiber pulp comprising treating the fiber with a suitable re ducing agent in aqueous solution with the later addition of carbon bi-sulphide thereto, after which the whole is subjected to superatmospheric pressure and heat.

11. The process of making fiber ulp comprising treating 9000 pounds of ii rous material with 500 pounds of lime, 12 pounds caustic soda in an aqueous solution of 36 barrels of water with the later addition of 10 pounds of carbon bi-sulphide thereto, after which the whole is subjected to superatmospherie pressure and heat.

12. The process of making fiber pulp comprising treating 9000 pounds of fibrous material with 500 pounds of lime, 12% pounds caustic soda in an aqueous solution of 36 barrels of water with the later addition of 10 pounds of carbon bi-sulphide thereto, after which the whole is subjected to steam under a pressure of 35 to pounds gauge for a period of 3 hours.

DELL FOREST HARBAUGI-I. 

